الفهرس 
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Abstract
The treatment of Class II malocclusions has always been a subject of great interest for orthodontists. The use of so-called “distalization” mechanics to correct Class II malocclusions is a common treatment modality. Many devices have been developed and used to distalize the maxillary molars and show positive clinical results. Some appliances need patient compliance but alternative methods termed noncompliance appliances have been presented to overcome the problem of compliance and correct Class II malocclusion efficiently. With the introduction of skeletal anchorage, the problem of loss of anterior anchorage with distalization was overcome.
In the current study, the mini-screw implant aided AMDA appliance was used for bilateral distalization of maxillary first molars. 12 patients All patients included were growing patients with mixed dentition or early permanent before the full eruption of maxillary second molar which considered as an antimere for distalization due to the correlated resistance. were recruited from the out-patient clinic of the Orthodontic Department of the Faculty of Dentistry Ain-Shams University. All patients required maxillary molar distalization as part of their orthodontic treatment plan. For each subject a standard full set of orthodontic records were taken pre and post distalization Two tomas miniscrews 8 mm in length, 1.6 mm in diameter were inserted 2-4 mm paramedian the appliance was disinfected and inserted into the patient mouth, ensuring that it parallel to the occlusal plane and the two symmetrical loops are posterior to the incisive foramen. A small portion of light-cure resin was added to cover the top of each implant head plus the ending of the ligature wires and the loops of the palatal arch wire to avoid plaque accumulation. Activation of the AMDA by unscrewing the distal screws to allow free distal sliding of the posterior part of the tubing system, the mesial stop screws are not altered.
Lateral cephalometric radiograph will be obtained before and after molar distalization for all participants The rate of tooth movement will be analyzed using computer software on digital models obtained by scanning orthodontic study casts taken before and after molar distalization. When a Class I molar relationship is obtained distalization will be considered complete, this will be assessed visually. All data will be tabulated and statistically analyzed.
Treatment results were assessed using lateral cephalometric radiographs and digital models. The records were acquired before treatment after achievement of molar Class I relationship. Lateral cephalometric radiographs were used to assess the effects of treatment on the skeletal, dental and soft tissues. Digital models were used to assess the rate of distalization.
Regarding the skeletal changes, AMDA showed insignificant changes in all following measurements SNA, SNB, ANB, PP/SN, MP/SN, facial height.
Regarding the first maxillary molars, our results showed a statistically significant distalization by 3.2 ±2.4mm and statistically significant distal tipping in relation to palatal plane by 6.08 ±4.8 degrees. Regarding molar extrusion, the results showed statistically insignificant extrusion.
Regarding the maxillary incisors, study results showed statistically significant ratiocination in relation to SN, PP, NA planes with significant retrusion in relation to NA plane.
Regarding soft tissues, study showed statistically insignificant changes in nasolabial angle and facial convexity. Additionally, both upper and lower lips were retracted in relation to E line.